Methods for joining polymeric composites using a hybrid friction/ultrasound technique for achieving desired weld characteristics

ABSTRACT

A method for use in efficiently joining together multiple workpieces to inhibit establishment of weld material in unwanted areas. The method uses a hybrid shaping-and-energizing system having a shaping tool and an ultrasonic horn. The method positions the hybrid shaping-and-energizing system proximate a workpiece, uses the shaping tool to form at least one recess in the proximate workpiece, and applies weld energy to the proximate workpiece using the ultrasonic horn. The recess is formed and the weld energy applied such that molten workpiece material becomes disposed within the recess, thereby inhibiting formation of weld material in the unwanted areas.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 14/476,213, filed on Sep. 3, 2014, which claims the benefit of U.S.Provisional Patent Application No. 61/874,403, filed on Sep. 6, 2013,the content of which is incorporated herein in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to joining polymeric compositesand, more particularly, to an apparatus and methods for joiningcomposites using a hybrid joining technique involving applying frictionand ultrasonic energy to the workpieces being joined. The friction andultrasonic operations can be performed in any order and at timessimultaneously, according to embodiments of the technology.

BACKGROUND

In automotive manufacturing, polymeric composites are being usedincreasingly due to their favorable characteristics, including beinglightweight, highly-conformable or shapeable, strong, and durable. Somecomposites are further colorable and can be finished to have most anydesired texture.

The increased use in automobiles includes, for instance, in instrumentand door panels, lamps, air ducts, steering wheels, upholstery, truckbeds or other vehicle storage compartments, upholstery, external parts,and even engine components. Regarding engine components, and otherunder-the-hood (or, UTH) applications, for instance, polymers areconfigured, and being developed continuously, that can withstand a hotand/or chemically aggressive environment. Regarding external parts, suchas fenders, polymers are being developed that are online paintabilityand have high heat and chemical resistance over longer periods of time.And many other potential usages in automotive applications are beingconsidered continuously.

With this trend, finding ways to efficiently and effectively joinpolymer components is becoming progressively important. Compressionmolding and post-mold joining techniques—e.g., ultrasonic welding—arebeing used more commonly.

Traditional techniques have various shortcomings. With reference to thefigures, and more particularly the first figure, FIG. 1 showsschematically a conventional ultrasonic welding arrangement 100including a welding horn 102 and two workpieces 104, 106 prior towelding.

In the illustrated step, the horn 102 is lowered, as indicated by downarrow, toward contacting a top workpiece 104 of the two. Once in contactwith the piece 104, an ultrasonic generator connected to the hornexcites high-frequency ultrasonic vibrations, which are passed throughthe horn to the piece. At the interface heat is generated and theworkpiece 104 begins to melt 200, as shown in FIG. 2.

FIG. 3 shows the arrangement 100 after it has been melted sufficientlyfor the molten material of the workpieces to connect the pieces 104, 106at a joint 300.

The technique has shortcomings including the formation of unwantedexcess, or squeeze-out, workpiece material 302 on the top surface of theproximate workpiece 104. The excess material develops at least in partbecause the workpiece material expands as it melts.

One option for handling this situation is to remove the excess material302 from the now-welded workpiece arrangement. This cleaning is ofcourse time consuming, eating up critical cycle time in themanufacturing process. Another shortcoming to this option is theenergy—e.g., manpower or robotic resources, to perform the cleaning.

The cleaning can also add significant other cost, such as cost ofpurchase, customizing (programming, etc.), and maintenance of cuttingmachinery—e.g., blade-based, or light-based cutting tools.

Further challenges arise whether cleaning the excess 302 prior to orafter the excess has cooled. Whether the excess has hardened by cooling,special care would need to be taken to ensure that the material 302 isremoved without affecting the balance of the cooling or cooled materialundesirably. Upsetting a surface portion of the cooling or cooledmaterial could affect cosmetic quality of the resulting part. It is alsocontemplated that rough removal of the excess 302, such as by chippingat the material after hardening, could upset an integrity of theconnection 300.

Another alternative is to use ultra-high-power ultrasonic energy. Whenmore ultrasonic energy is used, the top workpiece, and eventually thebottom one, melts more quickly, and so the desired welding 300 is formedmore quickly. In this way, less ancillary, lateral, workpiece materialis melted, and so less excess material formed. This approach also iscost prohibitive, though. Moreover, excess material could still form.

Still another alternative is conventional mechanical fastening. Theworkpieces can be screwed together, or connected by nuts and bolts, forinstance. These connections have shortcomings including unwanted addedweight, unsightly exposed portions of the fasteners, and possiblyless-robust joints.

SUMMARY

The present technology relates to a hybrid joining technique includingjoining composites using a hybrid joining technique involving applyingfriction and ultrasonic energy to the workpieces being joined. Thefriction and ultrasonic operations can be performed in any order and attimes simultaneously, according to embodiments of the technology. Theresult is a large and robust weld, especially as compared toconventional techniques.

The technique includes in one embodiment, for instance, mechanicallyshaping a workpiece in a manner facilitating effective and neatsubsequent ultrasonic welding of the workpiece with another workpiece.In a contemplated embodiment, the application of ultrasonic energy isnot fully subsequent to the friction application, as the ultrasonicenergy application can commence before the friction creation iscompleted. Friction-induced workpiece melting can occur simultaneouslywith ultrasound-induced workpiece melting. In either case, each of theseapproaches may be referred to as friction-assisted ultrasonic welding.Again, the result is a large and robust weld, especially as compared toconventional techniques.

The mechanical shaping in some embodiments melts and/or removes some ofthe workpiece material, facilitating subsequent ultrasound-inducedmelting of the workpiece.

The technique in one embodiment includes applying friction aftercommencement of ultrasonic energy application. In a particular case,friction generation is commenced (e.g., by a shaping tool describedfurther below) after commencement of applying ultrasonic vibrations toat least a proximate one of the workpieces being joined, and beforeconclusion of the application of the ultrasonic vibrations to theworkpiece(s). In this way, too, ultrasound-induced workpiece meltingoccurs simultaneously with friction-induced melting. In anotherparticular, and contemplated, case, the friction generation is commencedimmediately after conclusion of the application of the ultrasonicvibrations to the workpiece(s). The immediacy ensures that theworkpiece(s), molten and solid, do not cool, or cool by a minimaldegree, thus facilitating the subsequent friction induced melting. Andthe immediacy in some instances ensures that molten material from theultrasound operation remains so that the mechanical action of thefriction-inducing tool, or results of the mechanical action, can affectthat molten material, e.g., stir it, enhance its size, change its shapeas desired, and/or other. In any event, each of these approaches may bereferred to as ultrasonic-assisted friction welding, ultrasonic-assistedfriction stir welding, or the like. And, once again, the result is alarge and robust weld, especially as compared to conventionaltechniques.

Further reference is now made to the afore-mentioned embodiment in whichmechanically shaping of a proximate, first, workpiece, of the workpiecesbeing joined, is performed, to facilitate effective and neat subsequentultrasonic welding of the workpiece with another workpiece. Generally,the shaping involves creating one or more recesses in the firstworkpieces for accommodating molten workpiece material during thewelding. The mechanical shaping in some embodiments melts some of theworkpiece material, facilitating subsequent ultrasound-induced meltingof the workpiece.

Benefits of the techniques include reduced cycle time in welding, energyand resource savings, and neater resulting parts that are potentiallymore robust.

Time, energy, and resources are saved by obviating a need to remove froma top workpiece excess workpiece material developing in an undesiredposition during welding, such as above a primary surface of theworkpiece surface.

Cycle time may also be improved by expedited welding via channelingvibrations, and resulting heat, through one or more limited channels. Atleast one recess may be formed, for instance, so that while primaryworkpiece material remains directly below the ultrasonic horn, at leastsome lateral workpiece material, adjacent the primary material, isremoved. In this case, the high-frequency (HF) vibrations emitted by thehorn, and resulting heat, are channeled more quickly through the primarymaterial to an interface between the pieces being joined, than it wouldif the adjacent material was not removed—i.e., if the vibrations andheat needed to traverse both the primary and adjacent material inreaching to the interface for welding.

Parts lacking excess material would be cleaner, and parts joinedaccording to the present technology, requiring no excess-materialremoval, are expected to be cosmetically superior to parts joined underthe traditional technique requiring removal.

Other aspects of the present invention will be in part apparent and inpart pointed out hereinafter.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates schematically a conventional ultrasonic weldingarrangement including a welding horn and two workpieces prior to weldingthem together.

FIG. 2 shows the arrangement of FIG. 1 as welding is commenced.

FIG. 3 shows the arrangement as welding is completed, and unwantedexcessive, or squeeze-out, workpiece material formed.

FIG. 4 illustrates schematically a novel ultrasonic welding arrangementincluding the two workpieces to be joined and hybrid tooling comprisinga shaping tool, or shoulder, surrounding an ultrasonic welding horn,prior to welding, according to an embodiment of the present technology.

FIG. 5 shows a top plan view of the hybrid tooling of FIG. 4.

FIG. 6 shows the arrangement of FIG. 4 indicating a first operationwhereby the shoulder is lowered toward a proximate workpiece of theworkpieces being joined.

FIG. 7 shows the arrangement after the operation of FIG. 6, andindicates a subsequent operation whereby the shoulder is manipulated,e.g., rotated, to create at least one slot in the proximate workpiece.

FIG. 8 shows the arrangement after the operation of FIG. 7, andindicates a subsequent operation whereby the shoulder is retrieved fromits working position at the proximate workpiece.

FIG. 9 shows the arrangement after the operation of FIG. 8, wherein theslot has been formed and the shoulder withdrawn.

FIG. 10 shows the arrangement after the operation of FIG. 8, andindicates a subsequent operation whereby the ultrasonic welding horn islowered to the proximate piece for welding.

FIG. 11 shows the arrangement after the operation of FIG. 10, whereinthe horn has reached the proximate piece, just prior to commencement ofwelding.

FIG. 12 shows the arrangement after the operation of FIG. 10 and afterwelding has commenced.

FIG. 13 shows the arrangement after the operation of FIG. 12, aftersufficient welding is performed to cause molten workpiece material tobegin to fill a space created by the shoulder.

FIG. 14 shows the arrangement after the operation of FIG. 13, as weldingis continued and molten workpiece material begins to fill substantiallymost of the space created by the working of the shoulder.

FIG. 15 shows the arrangement upon completion of the welding andretrieval of the ultrasonic weld from the workpieces joined.

FIGS. 16-20 show the system being used according to an alternativeembodiment of the present technology.

DETAILED DESCRIPTION

As required, detailed embodiments of the present disclosure aredisclosed herein. The disclosed embodiments are merely examples that maybe embodied in various and alternative forms, and combinations thereof.As used herein, for example, “exemplary,” and similar terms, referexpansively to embodiments that serve as an illustration, specimen,model or pattern.

The figures are not necessarily to scale and some features may beexaggerated or minimized, such as to show details of particularcomponents. In some instances, well-known components, systems, materialsor methods have not been described in detail in order to avoid obscuringthe present disclosure. Therefore, specific structural and functionaldetails disclosed herein are not to be interpreted as limiting, butmerely as a basis for the claims and as a representative basis forteaching one skilled in the art to variously employ the presentdisclosure.

While the description includes a general context of computer-executableinstructions, the present disclosure can also be implemented incombination with other program modules and/or as a combination ofhardware and software. The term “application,” or variants thereof, isused expansively herein to include routines, program modules, programs,components, data structures, algorithms, and the like.

Applications can be implemented on various system configurations,including single-processor or multiprocessor systems,microprocessor-based electronics, combinations thereof, and the like. Incertain embodiments, some or all operations (e.g., controlling hornapplication) are performed by, or at least initiated by a computingdevice, such as a processor executing computer-executable instructionsstored or included at a computer-readable medium. And any one or moresteps of the process can be performed, initiated, or otherwisefacilitated by automated machinery, such as robotics.

I. General Overview of the Disclosure

The present disclosure describes a hybrid technique for joiningworkpieces, such as polymeric composites. The technology involves ahybrid joining technique including joining composites using a hybridjoining technique involving applying friction and ultrasonic energy tothe workpieces being joined. The friction and ultrasonic operations canbe performed in any order and at times simultaneously, according toembodiments of the technology. The result is a large and robust weld,especially as compared to conventional techniques.

While the descriptions, below, focus primarily on embodiments referredto in the Summary, above, as friction-assisted ultrasonic welding, theother embodiments described expressly and inherently herein are optionalaspects of the present technology. The technology can be implemented aswell according to other embodiments, such as the embodiments referred toin the Summary, above, as ultrasonic-assisted friction welding,ultrasonic-assisted friction stir welding, or the like. In all cases,the goal is to achieve large and robust welds, especially in comparisonto the welds made by conventional techniques.

FIGS. 16-20 show the system being used according to embodiments in whichthe ultrasonic energy application is commenced first. Aspects of theseembodiments can be varied, as described expressly and inherently herein.While the horn 406 is shown remaining in place in FIGS. 17 and 18, forexample, the horn 406 could be withdrawn prior to or while the shapingtool 404 is being lowered or begins rotating. And while the horn 406 isshown emanating welding energy (e.g., high-frequency ultrasonicvibrations) in FIGS. 18 and 19, the horn 406 could be withdrawn at thesestages, as mentioned, or still present in the lowered state, but notemanating the energy in association with FIG. 19, or with FIGS. 18 and19. A contemplated benefit of leaving the horn 406 in place, even if itis not emanating energy, is that the horn 406 surface might function tokeep molten workpiece material in place beneath the workpiece surface(see e.g., 1504 in FIG. 15) as desired during operation of the frictiontool 404.

Further reference is now made to the afore-mentioned embodiment in whichmechanically shaping of a proximate, first, workpiece, of the workpiecesbeing joined, is performed, to facilitate effective and neat subsequentultrasonic welding of the workpiece with another workpiece. By theshaping, one or more recesses are formed. The number of recesses, andtheir sizes, shapes, and positions are determined to facilitate weldingin a predetermined manner. The recesses facilitate welding at least byaccommodating molten workpiece material during welding.

It is also contemplated that, in some embodiments, welding is expeditedby presence of the one or more recesses. In one case, for example, withat least one recess formed so that primary workpiece material remainsdirectly below the ultrasonic horn, but at least some lateral workpiecematerial, adjacent the primary material, is removed, the ultrasonicvibrations to be emitted by the horn, and the heat generated thereby,will traverse more quickly to an interface between the pieces beingjoined, than it would if the adjacent material was not removed.

The mechanical shaping in some embodiments melts some of the workpiecematerial. Whether the mechanical shaping causes the workpiece materialto actually melt, it will heat the workpiece material. If ultrasonicwelding is commenced while the workpiece is still not, or at least notfully cooled, then this friction-induced pre-heating facilitates theultrasonic welding. For instance, less ultrasonic energy is needed tomelt pre-heated material.

The technique, whether the mechanical shaping causes the workpiecematerial to actually melt, can be referred to as a hybrid weldingtechnique, including mechanical and ultrasound operations—themechanical/friction-induced shaping, and possible melting, of theworkpiece and the ultrasound-induced melting facilitated by saidmechanical operations.

Other benefits include additional reduction of cycle, energy, andresources via obviation of any need to remove, from a proximateworkpiece of the two being joined, excess workpiece material developingin an undesirable location position during welding, such as above aprimary surface of the proximate workpiece.

Parts lacking excess material would be neater, and parts joinedaccording to the present technology, requiring no excess-materialremoval, are expected to be cosmetically superior to parts joined underthe traditional technique requiring removal.

It is also contemplated that a workpiece-to-workpiece connectionaccording to the present technology could have a higher integrity orrobustness than connections formed by conventional techniques. Aconnection being formed, or formed already, could be damaged by theconventional necessity to remove unwanted material from undesiredlocations. Upsetting a surface portion of a cooling or cooled materialcould, in addition to reducing cosmetic quality of the part, upset theconnection. Rough handling or chipping off of excess material could alsochip desired material and cause fractures in joint material. A fractureoriginating at the surface could propagate to the joint, or roughhandling of the parts could cause unwanted inter-part movement,upsetting the joint.

By obviating the removal function altogether, the present technologythus saves time, energy, resources, and integrity of the resulting partor product.

Time and energy can also be saved in embodiments in which the workpieceis pre-heated by the workpiece shaping (e.g., friction). Less time andenergy are required to melt the workpiece having been pre-heated assuch.

The system components, algorithm, and operations are described furtherbelow with reference to figures.

II. Process, Tooling, and Workpieces—FIGS. 4-15

The present technology is now described with reference to examplesystems, tooling, and workpieces. The figures are referenced tofacilitate understanding of the technology, and not to limit scopethereof.

Reference to directions herein, such as upper, lower, up, down, andlateral, are provided to facilitate description of the presenttechnology but does not limit scope of the technology. A description inwhich a servo horn is described as descending down upon a proximateworkpiece is not limited, for example, to the horn moving verticallydownward in the earth, or environment, frame. The horn in this case canbe moving from left to right, for example, in the environment frame.

Again, while the descriptions, below, focus primarily on embodimentsreferred to in the Summary, above, as friction-assisted ultrasonicwelding, the other embodiments described expressly and inherently hereinare optional aspects of the present technology. The technology can beimplemented as well according to other embodiments, such as theembodiments referred to in the Summary, above, as ultrasonic-assistedfriction welding, ultrasonic-assisted friction stir welding, or thelike.

Turning again to the figures, and more particularly, the fourth figure,FIG. 4 shows schematically the new ultrasonic welding arrangement 400prior to welding.

The arrangement 400 includes the two workpieces 104, 106 of FIG. 1 to bejoined.

The workpieces 104, 106 can include any of various materials, and haveany of a variety of shapes and sizes. In one example, the proximateworkpiece 104 has a thickness (top to bottom thickness in the figures)of between about 0.5 mm and about 5 mm.

Regarding material, the workpieces 104, 106 can include similar ordissimilar materials compared to each other. Regarding dissimilarworkpiece materials, one workpiece can be a plastic or other polymer,for instance, and the other can be steel, aluminum, an alloy, or othermetal, etc. Thus, the teachings of the present disclosure can be used tojoin a polymer (e.g., polymeric composite) to another polymer, or tojoin a polymer to a metal, for instance.

In one embodiment, the material 104, 106 includes polyethylene. In oneembodiment, the material includes polyethylene terephthalate (PET), highdensity polyethylene (HDPE) and/or ethylene vinyl alcohol (EVOH).

In one embodiment, at least one of the workpieces 104, 106 being joinedincludes a polymer. At least one of the workpieces 104, 106 can includesynthetic, or inorganic, molecules. While use of so-called biopolymers(or, green polymers) is increasing, petroleum based polymers are stillmuch more common.

Material of one or both workpieces 104, 106 may also include recycledmaterial, such as a polybutylene terephthalate (PBT) polymer, which isabout eighty-five percent post-consumer polyethylene terephthalate(PET).

In one embodiment one or both of the workpieces 104, 106 includes somesort of plastic. In one embodiment, the material includes athermo-plastic.

In one embodiment one or both of the workpieces 104, 106 includes acomposite. For example, in one embodiment one or both of the workpiecesincludes a fiber-reinforced polymer (FRP) composite, such as acarbon-fiber-reinforced polymer (CFRP), or a glass-fiber-reinforcedpolymer (GFRP). The composite may be a fiberglass composite, forinstance. In one embodiment, the FRP composite is a hybrid plastic-metalcomposite.

The material of the workpieces 104, 106 in some implementations includesa polyamide-grade polymer, which can be referred to generally as apolyimide.

Material of one or both workpieces 104, 106 may also include includespolyvinyl chloride (PVC).

In one embodiment, the material of the workpieces 104, 106 includesacrylonitrile-butadiene-styrene (ABS).

In one embodiment, the material of the workpieces 104, 106 includes apolycarbonate (PC).

Material of one or both workpieces 104, 106 may also comprise a type ofresin. Example resins include a fiberglass polypropylene (PP) resin, aPC/PBT resin, and a PC/ABS resin.

The workpieces 104, 106 may be pre-processed, such as heated andcompression molded prior to the welding.

The arrangement 400 further includes hybrid tooling 402 comprising ashaping tool 404 surrounding an ultrasonic-energy applicator, or horn406. One or both workpieces 104, 106 may be supported, at least in part,by a supporting structure, or supporting force 408.

The shaping tool 404 is configured in any appropriate manner forperforming the shaping functions described herein. In one embodiment,shaping-tool functions include primarily creating at least one slot,hole, recess, or other void in the proximate workpiece 104.

In one embodiment, the shaping tool 404 is primarily mechanical-based. Amechanical configuration can be configured to create the slot or void byway of friction, pressure, impression, cutting, or any combination ofthese, for instance.

For embodiments in which the material is removed to form the slot byfriction, the shaping tool 404 may be referred to as a friction tool.Workpiece material can be displaced, or removed, by movement of the tool404 in response to direct tool-to-workpiece contact, or friction, andpossibly also by heat generated by the friction.

As one benefit of the present technology, overall welding cycle timesaved, and process efficiency, improved because heat is generated in theworkpiece due to the—e.g., friction caused by the shaping tool on theworkpiece. Less energy is required to melt the workpiece pre-heated assuch, and so the welding process is expedited. Energy, e.g., electricalenergy is also saved as an amount of ultrasonic power needed is reducedwhen the part is pre-heated.

The shaping tool 404 of FIG. 4 is of this mechanical-based type. Theillustrated tool 404 is described further below in connection with FIGS.5-8.

According to another, contemplated, embodiment, the shaping tool 404 islight-based, such as a tool using a LASER. The tool 404 is configured tocreate a slot or void by displacing and/or removing material of theworkplace 104 using light-based (e.g., LASER) energy.

In another contemplated embodiment, the shaping tool 404 is configuredto apply heat to the workpiece to form a slot by burning workpiecematerial. The tool 404 could include, e.g., an electrode orquick-heating iron. In a further contemplated embodiment, the tool 404is configured to, or connected to a device configured to, vacuum thematerial as it is being melted or burned to form the slot. In anothercontemplated implementation, the heat is sufficient to burn, or char,the material so that the slot is formed as desired without developmentof excess material above the surface of the workpiece 104. The burningmay, for instance, evaporate some of the workpiece material to form theslot.

FIG. 5 shows a top, plan view of the hybrid tooling 402 of FIG. 4. Asshown, the shaping tool 404 surrounds the ultrasonic horn 406. In oneembodiment, the components 404, 406 are positioned adjacent each otherslidably, so that each can move with relative ease with respect to theother 406, 404.

In one embodiment, the relative configuration allows the relativemovement in the vertical direction. This flexibility allows, forinstance, the shaping tool 404 to be lowered and raised with respect tothe horn 406 and the proximate workpiece 104, and the horn to be loweredand raised with respect to the proximate workpiece 104, as describedfurther below in connection with FIGS. 6, 8-11, and 15.

In one embodiment, the relative configuration allows the shaping tool404 and the ultrasonic horn 406 to move with respect to each other inone or more directions in addition to or other than vertical. In a firstparticular embodiment, the configuration allows the shaping tool 404 torotate with respect to the horn 406 and the proximate workpiece. In asecond particular embodiment, in which there is no relative rotationalmovement between the shaping and horn tools 404, 406, the two rotatetogether with respect to the workpiece 104 to form the slot (704 in FIG.7). Though these two embodiments differ, the illustration of FIG. 7 isconsidered to show schematically operation under each of these twoembodiments toward forming the slot shown in FIG. 9.

With further reference to FIGS. 4 and 5, the horn 406 is shown having agenerally cylindrical shape, and circular top cross section, and theshaping tool 404 having an annular top profile. Shape of the horn is notlimited to this shape, and the horn may include any appropriate shape ofa wide variety of shapes.

Contemplated alternative shapes include a tall block having an oval,square, or other rectangular top profile. For these non-circularembodiments, the workpiece slot would not be formed by rotation of thetool 404, but rather pressure, or impression, for instance.

With continued reference to the figures, FIG. 6 shows the arrangement400 of FIG. 4 indicating by arrows 600, a first operation whereby theshaping tool, or shoulder 404, is lowered with respect to the horn 406and with respect to the proximate workpiece 104.

In a contemplated embodiment, for facilitating the relativeshoulder-to-horn motion, the shoulder 404 and horn 406 includecorresponding track elements (not shown in detail). One may include arelatively-small elongated protrusion while the other includes a smallvertical groove configured to slidably receive the protrusion. For thisembodiment, the shoulder 404 and horn 406 would rotate together in theoperation of FIG. 7.

In some embodiments, the shaping tool 404 and/or the ultrasound horn 406are configured and/or arranged in one or more ways to ensure theultrasonic functions are not hindered by the horn 406 contacting thetool. In one embodiment, the components 404, 406 are separated by asmall gap or space, least when and where the ultrasound is beingtransmitted.

In another embodiment, one or both components 404, 406 includesinsulation, such as an external/surface, or slightly internal,vibration-prohibitive insulating layer.

In still another embodiment, the components 404, 406 are separated by amaterial, such as a fluid that inhibits transfer of ultrasonicvibrations from the horn to the shaping tool. In a particularembodiment, the material also acts as a lubricant (e.g., fluid ordry/solid lubricant) between the components 404, 406, facilitatingrelative movement between the two 404, 406 (e.g., FIGS. 6, 7, 8, 10, and15). In a contemplated embodiment, the arrangement includes one or moreseals to encase the separating material, keeping it between thecomponents 404, 406.

As referenced, and any of the operations can be performed, initiated, orotherwise facilitated by automated machinery, such as robotics.Regarding the operation indicated by FIG. 6, for example, a robot (notshown in detail) can be configured and arranged (e.g., connected to theshoulder 404) to control the lowering of the shoulder 404. The robot canbe automated or controlled by automation embodied in, e.g., a computeror other electronic controller (not shown).

The controller, in one embodiment, includes a tangible computer readablestorage device, or memory. The memory is programmed with (i.e., stores)computer-executable instructions, or code, that, when executed by aprocessor, such as a processor of the controller, causes the processorto initiate and control motion of the shaping tool 404.

The controller controls a downward movement of the shaping tool 404, atotal distance, or displacement, of the movement, and a velocity, orrate of displacement and direction (e.g., down or up).

In one contemplated embodiment, at least one movement of at least of theshaping tool 404 and the horn 406 is controlled manually. One or bothmay be controlled, e.g., by motion initiated by personal force—e.g.,force of personnel in a manufacturing plant.

With continued reference to the figures, FIG. 7 shows by arrow anembodiment in which, as reference above, either the shaping tool 404 ismoved with respect to the horn 406 and proximate workpiece 104, or bothcomponents 404, 406 are moved together with respect to the workpiece104.

Shaping-tool movement is indicated by rotation arrow 700. The rotating,as with all tooling 400 robotics, or other automated machinery, and acontroller, as reference above regarding lowering the shaping tool 404to the proximate workpiece 104.

In one embodiment, rotation of the shaping tool 404 is started after theworkpiece has been brought into contact with the proximate workpiece104. In another embodiment, the rotation is started before the shapingtool 404 first contacts the workpiece 104.

While a tip 702 of the shaping tool 404 is shown schematically having asquared profile in FIGS. 4 and 6-15, the tips may have any appropriateshape for performing the functions, and accomplishing the goals,described herein. Instead of having the squared profile shown, the tipsare, in one embodiment, more pointed (not shown in detail). In oneembodiment, the point is formed by an angled line meeting a verticalside of the shaping tool to form the point, or by two angled linemeeting to form the point.

The tool 404 is configured (e.g., size, shape, and material) and used toshape, or shape and melt, the proximate workpiece 104 as desiredaccording to applicable tribological principles.

In a contemplated embodiment, the shaping tool 404 has one or morediscontinuities at its lower edge. The lower edge may include, forinstance, sharp protrusions and/or recesses or gaps. The arrangement insome cases could form teeth, such as teeth of a saw. The tool 404 mayinclude, or have one or more features analogous to, an annular cutter,drill, or router.

In one embodiment, the system includes a workpiece-removal sub-system(not shown in detail). The sub-system is configured and arrangedadjacent the tool 404 and proximate workpiece 104 to move displacedworkpiece material (e.g., workpiece material cut or scratched off, butnot melted) away from the tool 404 and workpiece 104. The sub-system caninclude, e.g., positive and/or negative air flow elements, such as afocused blower and/or suction or vacuum elements.

In one embodiment, the shaping tool 404 is lowered as it is rotating. Bythis dual-direction motion, the shaping tool 404 at least initially cutsor scrapes away workpiece material as it is lowered to contact theworkpiece 104.

As provided, the shaping tool 404 in one embodiment is lowered onto theproximate workpiece 104 with force sufficient to make an impression, orindentation in the workpiece, without, or at least before, any rotatingof the tool 404. In a contemplated case, the tool 404 is configured,arranged, and moved past an initial contact with the workpiece 104 inorder to, without tool rotation, form the depression, or slot—e.g., slot704 shown in FIG. 7. In another contemplated embodiment, the shapingtool 404 is configured, arranged, and operated to form the slot 704 bysuch pressure being applied while the tool 404 is emanating at least alow level of heat.

The shaping tool 404 may include any of a variety of materials withoutdeparting from the scope of the present technology. In one embodiment,the tool 404 is steel or another metal. Generally, the shaping tool 404includes a material that is harder than that of the proximate workpiece104.

Continuing with reference to the figures, as provided, FIG. 7 shows thearrangement 400 after the shaping tool 404 has been used, according toembodiments described, to create the slot 704.

The slot 704 has a shape corresponding to a configuration of at leastthe shaping tool 404. For instance, in embodiments in which the tool 404has an annular top profile, such as that shown in FIG. 5, the resultingslot 704 will have a similar profile.

The operation includes continuing to rotate and lower the shaping tool404. The tool is lowered to a desired depth, or vertical displacement.

As the shaping tool 404 continues to be rotated and lowered, theworkpiece 104 begins to heat locally due to the friction. In someembodiments, the workpiece 104 is heated to such a degree at this stagethat the workpiece 104 begins to melt. Friction-generated moltenmaterial is indicated in FIG. 8 by reference numeral 800.

The amount of friction required to accomplish workpiece 104 meltingcorresponds proportionally to a melting point of the workpiece 104.Relatively little friction would be required for a workpiece having arelatively low melting point. In one embodiment, one, or both, of theworkpieces 104, 106 has a melting point between about 150° and 300° C.Workpiece 104, 106 materials are described further below.

Various system and operating characteristics are set to achieve desiredresults. The characteristics can affect each other in various ways. Forinstance, an amount of friction-generated molten material 800 created isaffected by variables including the depth, or displacement, to which thetool 404 is lowered while rotating, tool 404 material and shape/geometry(e.g., hardness, whether toothed, etc.), workpiece 104 material (e.g.,melting point and thermal conductivity), the speed at which the tool islowered, etc.

An amount of time that the tool 404 is lowered and rotated can depend onthe speed that the tool will be rotated, tool 404 material andshape/geometry (e.g., hardness, whether toothed, etc.), workpiece 104material (e.g., melting point and thermal conductivity), the speed atwhich the tool is lowered, an amount of workpiece 104 material desiredto be removed and melted, a desired configuration (e.g., size and shape)of any desired friction-induced weld nugget, etc. Other suchrelationships will be apparent to one skilled in the art executing thetechnology taught herein.

As shown in FIG. 8, the workpiece can melt down all the way to aninterface 802 between the workpieces 104, 106. If hot enough, the meltedproximate-workpiece material 800 can initiate melting of top surfacematerial of the distal workpiece 106.

Even if the melted material 800 of the proximate workpiece 104 onlyreaches the interface and contacts the surface of the distal workpiece106, a friction-generated weld 800 joining the workpieces 104, 106 isformed.

FIG. 8 also shows a subsequent step of retrieving the shaping tool 404from the proximate workpiece 104. The retrieval is indicated by up arrow801.

FIG. 9 shows the arrangement 400 after the slot 704 has been formed(FIG. 7), and the shaping tool 404 withdrawn (FIG. 8).

FIG. 10 shows the arrangement 400 after the operation of FIG. 8, andindicates by arrow 1000 a subsequent operation whereby the ultrasonicwelding horn 406 is lowered to contact the proximate workpiece 104, asshown in FIG. 11.

The horn 406 can be lowered, and the subsequent ultrasonic welding (FIG.11) commenced at any of various timings with respect to the tool 404completing its work on the workpiece(s). In one embodiment, the horn 406is lowered to contact the proximate workpiece 104 while the tool 404 isstill rotating and in contact with the workpiece(s), for example. Inanother case, the horn 406 is lowered to contact the workpiece 104immediately after the tool 404 has stopped rotating and is about to belifted. In another case, the horn 406 is lowered to contact theworkpiece 104 while the tool 404 is being lifted or immediately afterthe tool 404 has been lifted.

In one contemplated case (not shown in detail), the horn 406 is loweredto contact the workpiece 104 before tool 404 starts rotating in thefirst place. The horn 406 can be lowered with the tool 404 in FIG. 6,for instance, and remains down in the steps shown by FIGS. 7 and 8.

Once the horn 406 is in contact with the proximate workpiece 104, anultrasonic generator connected to the horn 406 excites high-frequency(HF) ultrasonic vibrations. The vibrations are passed through the horn406 to the proximate workpiece 104, as indicated by reference numeral1200 in FIG. 12.

As the workpiece 104 receives the vibrations 1200, the excitementgenerates heat in the workpiece, causing the workpiece 104 to melt 1202,as also shown in FIG. 12. As provided, in one embodiment, one, or both,of the workpieces 104, 106 has a melting point between about 150° and300° C.

Once the shaping tool 404 stops rotating, heating of the workpiece(s)caused by the tool 404 will naturally cease. If there is a small windowof time between the tool 404 stopping and application of ultrasonicvibrations, the friction-generated molten material 800 and surroundingworkpiece material will naturally cool some. When this window issmaller, the friction-generated molten material 800 and surroundingworkpiece material will cool less.

In any event, even if the friction generated by the tool 404 is notdesigned to create any molten material, it is preferred for most casesthat window be small enough to ensure that some heat remains in theworkpiece(s) when the ultrasound is started. The pre-heating has variousbenefits. A primary benefit is that less ultrasonic energy will berequired to melt the workpiece material beneath the horn 406. Thepre-heating results in a savings of energy at this stage, and theultrasonic features can be used for a shorter period of time than ifthere were no pre-heating.

In one embodiment, the horn 406 is configured (e.g., by weight or springload) and/or controlled to apply a downward force on the workpiece 104during the welding. Thus, as the workpieces melt due to the ultrasonicvibrations, the horn 406 lowers some.

FIG. 13 shows the arrangement after the operation of FIG. 12, aftersufficient welding is performed to cause vibration-melted workpiecematerial 1202 to begin to fill any space 704 created by the shaping tool404. For embodiments in which the friction generated by rotation of theshaping tool 404 created molten material 800, the growingvibration-melted material 1202 eventually meets or joins with thefriction-melted material 800, as shown in FIG. 13.

If the vibration-melted material 1202 is energized (e.g., heated)enough, the material 1202 can heat any cooled friction-melted material800, re-melting any of it 800 if it had cooled and/or causing anyworkpiece material adjacent the previously-melted material 800 to melt.

In some embodiments, a single robust weld 1400 is formed, as shown inFIG. 14. As also shown in FIG. 14, as the ultrasonic welding iscontinued, molten workpiece 104 material begins to fill substantiallymost of the space 704 formed by the operation (FIG. 7) of the shapingtool 404. As also shown in FIG. 14, the molten material reaches theinterface 1400 between the parts 104, 106, for forming the weld joint.

FIG. 15 shows the arrangement upon completion of the welding and aretrieval action, indicated by upward arrow 1500, of the ultrasonic weldfrom the workpieces joined.

For embodiments in which a completely flat resulting surface is desired,the process described results, optimally, in a processed (heated andcooled) material surface 1502 that is substantially flush with theadjacent non-processed material 1504, as shown in FIG. 15. For this andeach embodiment, a desired cosmetic quality of the resulting product isachieved.

The welding process is configured to form the desired resulting finish.Example variables include, for instance, a shape and size of the horn406, a level of HF vibration applied, an amount of time that the weldingenergy is applied, a downward force of the horn, and a resultingdownward displacement of the horn in the welding.

In the contemplated embodiment, described above, in which the horn 406moves down during welding, the variables are configured so that thedesired surface finish, e.g., the flush finish mentioned, is formed. Thehorn 406 could during welding create a void into which a small amount ofexcess workpiece 104 material would fill when the horn is retrieved asshown by arrow 1500 in FIG. 15.

III. Various Features of the Technology

Some but not all of the benefits, advantages, motivations, and resultsof the present technology are described above, and some but not all ofthese are described in this section.

A hybrid friction and ultrasonic joining method to achieve high qualitywelds in joining multiple fiber-reinforced polymeric composites.

Benefits include reduced cycle time and improved process efficiency,cycle time, and joint quality.

Time is saved, and so process efficiency improved by, for instance, byobviating need to remove unwanted supra-surface molten, or melted andcooling or cooled workpiece material—e.g., workpiece material melted andpresent undesirably above the surface 1504.

Time is also saved, and process efficiency, improved because heat isgenerated in the workpiece due to the—e.g., friction caused by theshaping tool on the workpiece. Less energy is thus required to melt byultrasound the workpiece material that is adjacent the materialpre-heated by friction, whether the friction-heated material becomes orremains molten due to the friction—so long as the friction-heatedmaterial is warmed above a base temperature (e.g., room, ambient, orenvironmental temperature) at which the workpiece material would be atwithout application of the friction.

So, generally, the ultrasonic welding stage is shortened compared to thetime it would take without the friction-induced pre-heating. Energy,e.g., electrical energy is also saved as an amount of ultrasonic powerneeded is reduced when the workpiece is pre-heated.

Time might also be saved by the HF-vibration and heat channelingoccasioned by selectively removing workpiece material. Thehigh-frequency (HF) vibrations emitted by the horn, and resulting heat,might be channeled more quickly through the primary material, below thehorn, to an interface between the workpieces being joined, than it wouldif adjacent workpiece material had not been removed.

Joint quality, including integrity or robustness, is also improved.According to the present technologies, connections formed or beingformed are not damaged by the conventional necessity to remove unwantedworkpiece material. There is no risk, then, of upsetting a surfaceportion of a cooling or cooled, and so of reducing cosmetic quality.

The resulting weld joint is also larger than the weld would be is formedby the same horn and ultrasonic energy if no pre-friction shaping wereperformed.

Obviating the need to remove material also eliminates a risk ofaffecting a balance of the cooling or cooled material adjacent the extramaterial. As mentioned, in conventional systems, there is a chance that,by upsetting a surface portion of the cooling or cooled material, suchas by rough removal of the excess (e.g., chipping at hardened material),effects could transfer through the workpiece to also upset an integrityof the weld and possibly affecting cosmetics of the resulting product.

The benefits make welding in an assembling environment much more costeffective, and manufacturing of lightweight parts and products (e.g.,vehicles) more cost effective and results in better products.

IV. Conclusion

Various embodiments of the present disclosure are disclosed herein. Thedisclosed embodiments are merely examples that may be embodied invarious and alternative forms, and combinations thereof. As used herein,for example, “exemplary,” and similar terms, refer expansively toembodiments that serve as an illustration, specimen, model or pattern.

The figures are not necessarily to scale and some features may beexaggerated or minimized, such as to show details of particularcomponents. In some instances, well-known components, systems, materialsor methods have not been described in detail in order to avoid obscuringthe present disclosure. Therefore, specific structural and functionaldetails disclosed herein are not to be interpreted as limiting, butmerely as a basis for the claims and as a representative basis forteaching one skilled in the art.

The above-described embodiments are merely exemplary illustrations ofimplementations set forth for a clear understanding of the principles ofthe disclosure. Variations, modifications, and combinations may be madeto the above-described embodiments without departing from the scope ofthe claims. All such variations, modifications, and combinations areincluded herein by the scope of this disclosure and the followingclaims.

What is claimed:
 1. A method, for efficiently joining together multipleworkpieces, of a workpiece arrangement, while inhibiting incursion ofweld material into one or more unwanted areas of the arrangement,comprising: positioning a hybrid shaping-and-energizing systemcomprising a shaping tool and ultrasonic horn proximate a workpiece, theshaping tool being movably connected to the ultrasonic horn; forming,using the shaping tool, at least one recess in the proximate workpieceof the workpiece arrangement; and applying, using the ultrasonic horn,weld energy to the proximate workpiece of the workpiece arrangement;wherein the recess is formed, and weld energy applied, so that moltenworkpiece material becomes disposed within the recess, therebyinhibiting formation of weld material in the unwanted areas.
 2. Themethod of claim 1, wherein: forming the recess includes rotating theshaping tool while the shaping tool is in contact with the proximateworkpiece to generate sufficient friction to create the recess, being anannular recess; and the shaping tool is positioned around the ultrasonichorn.
 3. The method of claim 1, wherein automated machinery controls oneor more functions of the method.
 4. The method of claim 1, wherein: afirst workpiece and a second workpiece of the workpiece arrangement havedissimilar material; and at least one of the workpieces includespolymer.
 5. The method of claim 1, wherein the shaping tool is spacedfrom ultrasonic horn, defining an intervening gap, when the ultrasonichorn is positioned for applying ultrasonic vibrations, to inhibittransmission of vibrations from the ultrasonic horn to the shaping tool.6. The method of claim 1, wherein: in forming the recess using theshaping tool, material of the proximate workpiece to heat up; and theheating of the proximate workpiece facilitates welding in applying theweld energy to the proximate workpiece.
 7. The method of claim 1,wherein: in forming the recess using the shaping tool, material of theproximate workpiece to heat and partially melt the proximate workpiece;the applying is performed in a welding operation; and the heating andmelting of the proximate workpiece facilitates ultrasonic weldingoperation.
 8. The method of claim 1, wherein the tool and applicator areconfigured, arranged, and controlled according to a manner selected froma group consisting of: being configured, arranged, and controlled sothat operation of the ultrasonic horn to apply weld energy is commencedafter commencement of operation of the shaping tool to generate heat inthe workpiece by friction; being configured, arranged, and controlled sothat operation of the ultrasonic horn to apply weld energy is commencedbefore commencement of operation of the shaping tool to generate heat inthe workpiece by friction; being configured, arranged, and controlled sothat operation of the ultrasonic horn to apply weld energy is commencedafter conclusion of operation of the shaping tool to generate heat inthe workpiece by friction; and being configured, arranged, andcontrolled so that operation of the shaping tool to generate heat in theworkpiece by friction is commenced after conclusion of operation of theultrasonic horn to apply weld energy.
 9. The method of claim 1, wherein:forming the recess generates heat in the proximate workpiece, meltingworkpiece material; and applying the weld energy using the ultrasonichorn is commenced according to a timing selected from a group of timingsconsisting of: after commencement of forming the recess and melting theworkpiece by friction; before commencement of forming the recess andmelting the workpiece by friction; after conclusion of forming therecess and melting the workpiece by friction; and after conclusion ofapplying the weld energy using the ultrasonic horn.
 10. A method, forefficiently joining together multiple workpieces, of a workpiecearrangement, while inhibiting incursion of weld material into one ormore unwanted areas of the arrangement, comprising: positioning a hybridshaping-and-energizing system comprising a shaping tool and ultrasonichorn proximate a workpiece, the shaping tool being movably connected tothe ultrasonic horn; forming, using the shaping tool, at least onerecess in a proximate workpiece of the workpieces to be joined; andapplying, using the ultrasonic horn, weld energy to the proximateworkpiece, wherein the weld energy causes at least a portion of theproximate workpiece to form molten material that is disposed within theat least one recess, thereby inhibiting formation of weld material inthe unwanted areas.
 11. The method of claim 10, wherein: forming therecess includes rotating the shaping tool while the shaping tool is incontact with the proximate workpiece to generate sufficient friction tocreate the recess, being an annular recess; and the shaping tool ispositioned around the ultrasonic horn.
 12. The method of claim 10,wherein automated machinery controls one or more functions of themethod.
 13. The method of claim 10, wherein: a first workpiece and asecond workpiece of the workpiece arrangement have dissimilar material;and at least one of the workpieces includes polymer.
 14. The method ofclaim 10, wherein the shaping tool is spaced from ultrasonic horn,defining an intervening gap, when the ultrasonic horn is positioned forapplying ultrasonic vibrations, to inhibit transmission of vibrationsfrom the ultrasonic horn to the shaping tool.
 15. The method of claim10, wherein: in forming the recess using the shaping tool, material ofthe proximate workpiece to heat up; and the heating of the proximateworkpiece facilitates welding in applying the weld energy to theproximate workpiece.
 16. The method of claim 10, wherein: in forming therecess using the shaping tool, material of the proximate workpiece toheat and partially melt the proximate workpiece; the applying isperformed in a welding operation; and the heating and melting of theproximate workpiece facilitates ultrasonic welding operation.
 17. Themethod of claim 10, wherein the tool and applicator are configured,arranged, and controlled according to a manner selected from a groupconsisting of: being configured, arranged, and controlled so thatoperation of the ultrasonic horn to apply weld energy is commenced aftercommencement of operation of the shaping tool to generate heat in theworkpiece by friction; being configured, arranged, and controlled sothat operation of the ultrasonic horn to apply weld energy is commencedbefore commencement of operation of the shaping tool to generate heat inthe workpiece by friction; being configured, arranged, and controlled sothat operation of the ultrasonic horn to apply weld energy is commencedafter conclusion of operation of the shaping tool to generate heat inthe workpiece by friction; and being configured, arranged, andcontrolled so that operation of the shaping tool to generate heat in theworkpiece by friction is commenced after conclusion of operation of theultrasonic horn to apply weld energy.
 18. The method of claim 10,wherein: forming the recess generates heat in the proximate workpiece,melting workpiece material; and applying the weld energy using theultrasonic horn is commenced according to a timing selected from a groupof timings consisting of: after commencement of forming the recess andmelting the workpiece by friction; before commencement of forming therecess and melting the workpiece by friction; after conclusion offorming the recess and melting the workpiece by friction; and afterconclusion of applying the weld energy using the ultrasonic horn.
 19. Amethod, for efficiently joining together multiple workpieces, of aworkpiece arrangement, while inhibiting incursion of weld material intoone or more unwanted areas of the arrangement, comprising: positioning ahybrid shaping-and-energizing system comprising a shaping tool andultrasonic horn proximate a workpiece, the shaping tool being movablyconnected to the ultrasonic horn; forming, using the shaping tool, atleast one recess in a proximate workpiece of the workpieces to bejoined, wherein the shaping tool causes a portion of the proximateworkpiece within the recess to form molten material that becomesdisposed within the; and applying, using the ultrasonic horn, weldenergy to the proximate workpiece adjacent the recess, wherein the weldenergy causes the proximate workpiece to form molten material that thatjoins the molten material disposed within the recess, thereby inhibitingformation of weld material in the unwanted areas.
 20. The method ofclaim 19, wherein: applying the weld energy using the ultrasonic horn iscommenced according to a timing selected from a group of timingsconsisting of: after commencement of forming the recess and melting theworkpiece by friction; before commencement of forming the recess andmelting the workpiece by friction; after conclusion of forming therecess and melting the workpiece by friction; and after conclusion ofapplying the weld energy using the ultrasonic horn.